1. Field of the Invention
The present invention relates to self-loading or semi-automatic firearms having an improved action and gas system, and more particularly to such firearms having a bullpup configuration.
2. Description of Related Art
Firearms, particularly those that are built to fire powerful cartridges such as the .50 BMG (.50 caliber Browning Machine Gun) round requires various devices to help reduce the recoil to an acceptable level while operating the weapon. Firearms that operate as above are known either as recoil or gas operated.
A recoil operated firearm generally allows the barrel (locked with the breech) to recoil rearwards within the receiver, and at a given point the barrel separates from the breech halting its rearward travel, whilst the breech mechanism continues rearwards extracting and ejecting the spent case. On its return stroke, the breech mechanism picks up a fresh round and loads it into the chamber.
To reduce the strong recoil, a muzzle brake may be attached to the front of the barrel. However, because this type of weapon relies on recoil to cycle the weapon, the muzzle brake's efficiency has to be limited, otherwise it will reduce the recoil necessary to operate the reloading cycle of the weapon. Further, because the barrel recoils inside the receiver, the receiver is heavy and complex in design, as it has to provide strong anchor points for the barrel recoiling system and the springs necessary for both the barrel and breech, that both operate separately during the cycle of operation.
Generally, in a gas operated weapon, a muzzle brake is still needed to reduce the recoil, which can be more efficient in its function, since the cycling of the weapon is not dependent on the recoil of the weapon. A gas operated weapon with a very efficient muzzle brake can be lighter in weight and shorter when having a “bullpup” configuration.
Additionally, gas operated and recoil operated firearms, in their current design and configuration, impede the design of shorter and more compact larger caliber firearms. Generally, the length of the breech system is determined by the length of the cartridge case and bullet and the firing system and positioned behind the magazine and able to reach the firing pin in the breech bolt. In addition, the receiver should be of sufficient length to allow full rearward travel of the breech to fully extract and eject the spent case and re-arming the hammer ignition system.
Furthermore, conventional rifles have their firing mechanisms positioned behind the magazine and ahead of the stock. A more recent configuration called a “bullpup” places the firing mechanism in front of the magazine eliminating the need for a separate stock and reduces the overall length of the firearm and its weight accordingly.
Firearms having bullpup configurations are known in the art. For example, one type of firearm having a bullpup configuration is the Steyr AUG. The Steyr AUG is a bullpup assault rifle used in several countries such as Austria and Australia. However, various other types of firearms having bullpup configurations are known in the art.
However, conventional bullpup rifles with a trigger positioned in front of the magazine are generally not practical for larger cartridges. The trigger may be inconveniently positioned too far forward causing excessive trigger pull or decreasing the precision of the firearm.
Therefore, there is a need for a self loading bullpup firearm with a compact breech and hammer mechanisms in smaller configurations which are not restricted by the overall length of the larger cartridge such as the .50 BMG and therefore reduces the overall length and weight of the firearm.